High-speed, sensitive drilling attachment



Nov. 22, 1960 w. F. OCENASEK 2,960,893

HIGH-SPEED, SENSITIVE DRILLING ATTACHMENT Filed July 25, 1957 3Sheets-Sheet 1 46 u l Qiff, f/ (F a I 42 I\ 11 I INVENTOR. 43 44 William2'. Ocenasek BYEZ ATTORNE'Z Nov. 22, 1960 w. F. OCENASEK 2,960,893

HIGH-SPEED, SENSITIVE DRILLING ATTACHMENT Filed July 25. 1957 3Sheets-Sheet 2 IN VEN TOR. Q/z'ZZz am I? Ocenase/f BYZZ ' 6 ATTORNEYNov. 22, 1960 w. F. OCENASEK HIGH-SPEED, SENSITIVE DRILLING ATTACHMENTFiled July 25. 1957 3 Sheets-Sheet 3 INVENTOR. Mil/[am F UeenasakATTQRNEY Unite States HIGH-SPEED. SENSITIVE DRILLING ATTACHlVIEN TWilliam Ferdinand Ocenasek. 880 NE. 113th St., Miami 38, Fla.

Filed July 25, 1957, Ser. No. 674,178

4 Claims. (Cl. 77-55) This invention relates to a high-speed sensitivedrilling attachment to conventional large drill-presses.

In the prior art when a piece of work necessitated the drilling of largeholes, over 3 and of holes of smaller diameter on an assembly line, thedrilling of the small holes was always a problem. The assembly line hadto be interrupted, the work piece had to be taken out, to a small drillpress, and after the completion of the drilling of the small holes, thepiece was returned into the assembly with a resulting loss of time andeffort, upsetting progress and schedules. The conventional drill pressesfor drilling small holes, under fi tend to be inaccurate, and areimpractical for drilling soft metals. The conventional small drillpresses do not have the speed nor the vibration-free operation,necessary for precise small hole drilling and they do not have thesensitivity for drilling very small holes.

The primary object of the invention is to provide an attachment forsmall drills to a conventional drill press.

Another object of the invention is a high-speed attachment of such atype, which decreases vibrations in the drilling operations for thepurpose of accurately drilling precise small holes.

Yet another object of this invention is to provide an attachment of thetype described which extends the range of the drilling chuck, and makesit possible to locate it on the arc of a pre-determined radius from themain drill spindle.

Still another object of the present invention is to provide asmall-drill attachment to a conventional large drill press, whichattachment permits working on a larger piece of material, than could benormally accommodated on a conventional large drill press.

Another object of the invention is to provide an attachment of the typedescribed, which is easily mountable and easily removable without lossof time, and which permits selective drilling of larger holes by themain drill press and small holes by the attachment, without additionalexpensive equipment, interruptions, and consequent loss of time.

Yet another object of the invention is to provide a sensitive control ofthe pressure exerted against the work piece by the drill.

Another object of the invention is to provide an attachment as describedenabling the operator to utilize a driving pulley and a driven pulley ofa relative ratio permitting a speed up to 20,000 rpm. and more.

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following detailed description when considered inconnection with the accompanying drawings in which like referencenumerals designate like parts throughout the figures thereof andwherein:

Figure 1 shows a vertical cross-sectional view through the center planeof a preferred embodiment of the invention in place on a drill press.

Figure 2 illustrates a front view of the assembly.

Figure 3 shows a plan view of the drive only.

Figure 4 is a plan view of belt tensioning arrangement, forming a partof the invention.

Figure 5 is a vertical cross-sectional view through the central plane ofbelt idler unit, shown in Figure 4.

Referring now to the drawings, wherein like reference charactersdesignate like or corresponding parts throughout the several views,there is shown in Figure 1 a conventional drill press spindle showndesignated as 1.

The attachment of the present invention is mounted on a conventionaldrill press, such as described in applicants prior US, Patent No.2,072,646, and is not self-supporting. The entire main drill press isnot shown, but only the portion of the main spindle 1 and spindle quill3 required for the mounting. The main spindle 1 is threaded on the lowerend and is provided with a locking nut 9. The chuck of the conventionaldrill press is replaced by a light drive-pulley 4. The bore of thedriving pulley, in this instance, is provided with a bushing, which hasa tapered slot for a key 2b. The bushing has a shoulder 2a, which isclamped to the main spindle by locking nut 9. A key retaining screw, 20,serves to retain key 2b. While the bushing in Figure l is shown tapered,different types of bushings will be used for adapting the attachment todrill presses with difierent sizes of main spindles. The bore of thedriving pulley is of a constant diameter so that merely changing thebushing 2 makes this attachment interchangeable with any conventionaldrill press. The spindle quill of the drill press is shown as 3. Thesurface of the outer rim of the drive-pulley is curved into an oblongtop to maintain a fiat belt 11 centered on pulley 4. The belt should beflexible, preferably of a rubberized fabric, to eliminate vibrations.

The pulley 5 drives the attachment-drill press spindle 6. It issupported in ball bearings 7, mounted in frame 10. For simplification ofproduction the mounting of the bearings 7 in frame 10 is accomplished bymeans of bushings 29, upper, and 22, lower. The housings of the ballbearings are press-fitted onto the pulley unit 5 and into the bushings,thus leaving the spindle 6 free to slide vertically through the innerboring of the pulley unit. The upper hall-bearing bushing 20 is heldfirmly in place in frame 10 by means, such as a clamp locking bolt orscrew lila. Rotation of the spindle by' the pulleyunit is accomplishedby means such as splines, or a pair of keys 8, mounted in thepulley-unit and in conjunction with long key ways 80, machined in thespindle, as shown.

The upper portion of the frame of the attachment is shown in Figure 3reinforced by three mutually perpendicular ribs 10b on top of the frameIll. For a fourth rib, which would complete the reinforcing, the clamp10c is substituted. The attachment is fastened to the main spindle quill3 by means of this clamp 100, which is tightened by locking bolts 10a.The clamping arrangement of the attachment enables the operator toposition it at any desired angle in the horizontal plane and verticallyalong the quill of the main drill press.

The center of the attachment-spindle 6 is spaced preferably 5" from thecenter of the main drill-press spindle. Since the attachment can befastened at any horizontal angle about the main quill, the center of theattachmentspindle can be located, in such an instance, on the arc of aradius of 5 inches from the center of the main spindle.

This feature permits a conventional drill press to accommodate a largerpiece of work than would be possible without the attachment. Alsodrilling of holes in various locations between 3 and 13 inches from thepedestal of the conventional main drill having the drill spaced 8" fromits pedestal, may be accomplished without relocating the work piece. Thequill 12 of the attachmentdrill has a rack 13 and pinion 14. The teethof the rack have a fine pitch. The pinion is manually operated 3 V byahand'wheel a'nd' by handles 15a. The quill 12 slides within frame 10vertically. With the quill 12 again are located two high-speedball-bearings 16 and 1611, which are press-fitted on the enlarged lowerend of spindle 6. Lubricating means 17, are provided. The lubrication ofthe top ball-bearings 7 is provided through oil cap 18. An upper spindlecover is shown as 19. The

oil cup is placed in the terminal opening 18a. A protective belt cover21 surrounds the assembly. A retaining collar 23 holds ball bearing 16in place.

Referring to Figure 2, stop depth gauge collar 24 is fastened to thequill 12 and a stop depth gauge locking bolt 24a is provided. The depthgauge column 25 is used to adjust the depth of drilling in va fixedposition. The depth gauge column retaining nuts are shown as 26a and26b. Plate 27, fastened to the top of the column serves as a depthindicating pointer. A screw 27a holds the pointer to the depth gaugecolumn. The depth to which the attachment will operate is controlled bythe position of the depth limiting clamp 28. This clamp is adjusted inposition on the column 25 and locked to the column by the locking handle29. Since the column 25 is attached to the quill 12, it must move withthe said quill when the wheel 15 is rotated. When the depth limitingclamp strikes the projection ltle on the frame, the downward motion ofthe quill 12 is stopped. The vertical distance which the quill moved isindicated by the pointer on a depth gauge indicator plate 30, which isfastened to frame 10 by rivets 39a. The depth gauge unit is shown inFigures 1, 2 and 3, and has the function of limiting the depth ofpenetration of the drill. Handwheel 15 is mounted on pinion shaft 14aand is held in place by washer 32 and locking nut 31.

Torsion-spring 34 is fastened to the pinion 14 for the purpose ofbalancing the weight of the quill, spindle, and chuck, and forautomatically returning the quill 12 to its uppermost position. Atorsion-spring housing 33 is provided for protection and for adjustmentof the torsion-spring. A washer 35 with nuts 36 secures the pinion shaftand torsion spring in position.

One end of the torsion suring is fastened to the pinion shaft 14 and itsother end is attached to the spring housing 33. Tension of the spring iscontrolled by turning the spring housing like a knob. Projecting keys 45on frame 10 engage corresponding slots in the spring housing. See Fig.2. Thus the torsion spring tension can be set and changed at will andthe housing locked in position by loosening nuts 36 and re-tighteningafter adjustment of the housing.

The function of the belt idler unit, shown in Figures 1, 3, 4, and 5 isto control the tension of the flat belt 11. The flat belt preventscreation of excessive heat. The belt idler unit runs on idler shaftwhich is inserted in slot '46 provided in frame 10. The idler shaft 40has two fiat sides in way of the slot and parallel to the sides of theslot so that the shaft may be translated in and along slot 46 but cannotrotate herein. The tensioning is accomplished manually by moving thebelt idler unit with handle 47. A pulley ring 41 is pressed over theball bearing housing 42 and thus provides a wider surface for engagingthe driving belt. The ball-bearing housing 42 is pressed onto the idlershaft 40. A washer 43 in conjunction with screw 44 helps to retain theballbearing housing on the idler shaft.

. A flinger 37 is provided to prevent dirt, metal chips or otherimpurities from entering quill 12 and from damaging ball bearings. Thechuck of the drill-press-attachment is shown at 38.

The high speed spindle 6 and all high speed parts are to be balancedafter assembly.

From the above description and drawings, additional alternativeimprovements will become obvious to those skilled in the art:

Optionally, a drill chuck shown as 44, may be added toa bushing of thedriving pulley and the attachment of the present invention may be kepton the main drill continuously. Thus large and small holes may bedrilled at will without making changes to the attachment. The attachmentmay be provided with means to fold it by including a hinge and clamparrangement for a vertical folding motion. Thus it could be folded outof the way and provide space for use of themain drill withoutdismantling the attachment.

As a summary it is stressed that, contrary to all experiences of theprior art, this invention utilizes a conventional multiple low-speeddrill press such as from /2 to 1", up to 5,000 r.p.m., more or less, asa driving unit of, and in combination with, a novel sensitivemultiplehigh-speed, minimum-weight and fine-mechanics drill presssensitive attachment of a small bore of and less and with an rpm. of20,000 more or less.

While only a preferred embodiment of the invention has been shown in theannexed drawings and described in the specification above, it iscontemplated to cover any variations, changes and modifications of theexample of the invention herein chosen for the purposes of thedisclosure, which do not constitute departures from the spirit and scopeof the invention set forth in the appended claims.

What I claim is:

1. A high-speed drilling attachment to a conventional multiple-low-speeddrill press functioning as a main drill and including a quil and apower-driven spindle journaled in the quill for rotation on a fixed axiscomprising, in combination, a radial-arm frame including means integraltherewith releasably clamping said frame to the quill of said maindrill, the distal end of said frame having upper and lower spaced boreshaving a common axis parallel with and radially offset from said fixedaxis, said upper bore being split, an upper bushing fitting said upperbore to be axially adjustably clamped therein and having adownwardly-facing counterbore, a lower bushing fitting the upper end ofsaid lower bore, a quill axially transla-tably fitting said lower borebelow said lower bushing, a spindle having a lower cylindrical portionjournaled in said quill, and an upper splined portion of reduceddiameter, upper and lower anti-friction bearings each including innerand outer races, the outer race of said upper bearing having a press fitwithin the counterbore of said upper bushing, the outer race of saidlower bearing having a press fit in said lower bushing, a driven pulleyhaving integral coaxial sleeves extending centrally from the respectivesides thereof, each sleeve fitting and journaled in the inner race of arespective one of said bearings, said driven pulley having a maximumdiameter less than said upper bore, and key means fixed with said pulleywithin the bore thereof and slidably fitting the splines of saidspindle.

2. The combination as recited in claim 1, a driving pulley removablyfixed to the lower end of the spindle of the main drill press, a fiatbelt connecting said pulleys, an idler pulley, and means mounting saididler pulley on said frame for engagement with said belt and foradjustment toward and from the common plane of said axes.

3. A high-speed drilling attachment to a conventional multiple-low-speeddrill press functioning as a main drill and including a main quill and apower-driven spindle journaled in the main quill for rotation on a fixedaxis and for axial translation as a unit with said main quill,comprising, in combination, a radial-arm frame having a split main boresized to have a smooth fit about said main quill, clamping means carriedby said frame to contract said main bore and releasably fix said framewith said main quill, there being a second bore in the distal end ofsaid frame and comprising upper and lower axiallyspaced portions, firstand second bushings each fitting a respective portion of said secondbore, upper and lower antifriction bearings having outer racespress-fitting a respective one of said bushings to define a common axisparallel with and radially offset from the axis of said power-drivenspindle, an axially-apertured driven pulley between said bearings andhaving integral oppositelydisposed sleeve-like extensions fitting theinner race of each said bearing, respectively, a second quill fittingthe lower portion of said second bore for axial translation therein, asecond spindle journaled in said second quill and passing centrallythrough said pulley, a spline connection between said pulley and secondspindle, and a driving pulley rigidly connected with said power-drivenspindle coaxially thereof and in coplanar relation with said drivenpulley.

4. A high-speed drilling attachment to a conventional multiple-low-speeddrill press functioning as a main drill and including a main quill and apower-driven spindle journaled in the quill for rotation on a fixed axiscomprising, in combination, a radial-arm frame having first and secondlaterally-spaced parallel bores, said first bore being split andsmoothly fitting about said main quill, clamping means carried by saidframe to contract said first bore and unitize said main quill and frame,said second bore being in the distal end of said frame and comprisingupper and lower axially-aligned spaced portions first and secondbushings each fitting a respective portion of said second bore, upperand lower anti-friction bearings including outer races press-fitting arespective one of said bushings to define a common axis parallel withthe axis of said power-driven spindle, an axially-apertured drivenpulley between said bearings and having integral, oppositely-disposedsleeve-like extensions fitting the inner race of each said bearing,respectively, a second quill mounted within the lower portion of saidsecond bore for axial translation therein, a second spindle having amain portion and an upper end portion of reduced diameter, bearingsjournaling the main portion of said spindle within said second quill foraxial translation as a unit therewith, a spline connection between saiddriven pulley and the reduced upper end portion of said second spindle,a driving pulley rigidly connected with the lower end of saidpower-driven spindle, said pulleys being coplanar for direct beltconnection.

References Cited in the file of this patent UNITED STATES PATENTS850,204 Baumeister Apr. 16, 1907 1,416,777 Bayrer May 23, 1922 2,072,646Ocenasek Mar. 2, 1937 2,396,733 Wiken et al Mar. 19, 1946

